C++ SERIAL_S函数代码示例

void serial_format(serial_t *obj, int data_bits, SerialParity parity, int stop_bits)
{
    struct serial_s *obj_s = SERIAL_S(obj);
  
    if (data_bits == 9) {
        obj_s->databits = UART_WORDLENGTH_9B;
    } else {
        obj_s->databits = UART_WORDLENGTH_8B;
    }

    switch (parity) {
        case ParityOdd:
            obj_s->parity = UART_PARITY_ODD;
            break;
        case ParityEven:
            obj_s->parity = UART_PARITY_EVEN;
            break;
        default: // ParityNone
        case ParityForced0: // unsupported!
        case ParityForced1: // unsupported!
            obj_s->parity = UART_PARITY_NONE;
            break;
    }

    if (stop_bits == 2) {
        obj_s->stopbits = UART_STOPBITS_2;
    } else {
        obj_s->stopbits = UART_STOPBITS_1;
    }

    init_uart(obj);
}

void serial_irq_handler(serial_t *obj, uart_irq_handler handler, uint32_t id)
{
    struct serial_s *obj_s = SERIAL_S(obj);
  
    irq_handler = handler;
    serial_irq_ids[obj_s->index] = id;
}

/**
 * Abort the ongoing RX transaction It disables the enabled interrupt for RX and
 * flush RX hardware buffer if RX FIFO is used
 *
 * @param obj The serial object
 */
void serial_rx_abort_asynch(serial_t *obj)
{
    struct serial_s *obj_s = SERIAL_S(obj);
    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];

    // disable interrupts
    __HAL_UART_DISABLE_IT(huart, UART_IT_RXNE);
    __HAL_UART_DISABLE_IT(huart, UART_IT_PE);
    __HAL_UART_DISABLE_IT(huart, UART_IT_ERR);

    // clear flags
    volatile uint32_t tmpval __attribute__((unused)) = huart->Instance->RDR; // Clear RXNE
    __HAL_UART_CLEAR_IT(huart, UART_CLEAR_PEF);
    __HAL_UART_CLEAR_IT(huart, UART_CLEAR_FEF);
    __HAL_UART_CLEAR_IT(huart, UART_CLEAR_NEF);
    __HAL_UART_CLEAR_IT(huart, UART_CLEAR_OREF);

    // reset states
    huart->RxXferCount = 0;
    // update handle state
    if (huart->RxState == HAL_UART_STATE_BUSY_TX_RX) {
        huart->RxState = HAL_UART_STATE_BUSY_TX;
    } else {
        huart->RxState = HAL_UART_STATE_READY;
    }
}

/**
* Get index of serial object TX IRQ, relating it to the physical peripheral.
*
* @param obj pointer to serial object
* @return internal NVIC TX IRQ index of U(S)ART peripheral
*/
static IRQn_Type serial_get_irq_n(serial_t *obj)
{
    struct serial_s *obj_s = SERIAL_S(obj);
    IRQn_Type irq_n;

    switch (obj_s->index) {
        case 0:
            irq_n = USART1_IRQn;
            break;

        case 1:
            irq_n = USART2_IRQn;
            break;

#if defined(USART3_BASE)
        case 2:
            irq_n = USART3_IRQn;
            break;
#endif
#if defined(UART4_BASE)
        case 3:
            irq_n = UART4_IRQn;
            break;
#endif
#if defined(UART5_BASE)
        case 4:
            irq_n = UART5_IRQn;
            break;
#endif
        default:
            irq_n = (IRQn_Type)0;
    }
    
    return irq_n;
}

void serial_break_set(serial_t *obj)
{
    struct serial_s *obj_s = SERIAL_S(obj);
    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
    
    HAL_LIN_SendBreak(huart);
}

/** 
 * Begin asynchronous RX transfer (enable interrupt for data collecting)
 * The used buffer is specified in the serial object, rx_buff
 *
 * @param obj        The serial object
 * @param rx         The buffer for sending
 * @param rx_length  The number of words to transmit
 * @param rx_width   The bit width of buffer word
 * @param handler    The serial handler
 * @param event      The logical OR of events to be registered
 * @param handler    The serial handler
 * @param char_match A character in range 0-254 to be matched
 * @param hint       A suggestion for how to use DMA with this transfer
 */
void serial_rx_asynch(serial_t *obj, void *rx, size_t rx_length, uint8_t rx_width, uint32_t handler, uint32_t event, uint8_t char_match, DMAUsage hint)
{
    // TODO: DMA usage is currently ignored
    (void) hint;

    /* Sanity check arguments */
    MBED_ASSERT(obj);
    MBED_ASSERT(rx != (void*)0);
    MBED_ASSERT(rx_width == 8); // support only 8b width
    
    struct serial_s *obj_s = SERIAL_S(obj);
    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];

    serial_enable_event(obj, SERIAL_EVENT_RX_ALL, 0);
    serial_enable_event(obj, event, 1);
    
    // set CharMatch
    obj->char_match = char_match;
    
    serial_rx_buffer_set(obj, rx, rx_length, rx_width);

    IRQn_Type irq_n = serial_get_irq_n(obj);
    NVIC_ClearPendingIRQ(irq_n);
    NVIC_DisableIRQ(irq_n);
    NVIC_SetPriority(irq_n, 0);
    NVIC_SetVector(irq_n, (uint32_t)handler);
    NVIC_EnableIRQ(irq_n);

    // following HAL function will enable the RXNE interrupt + error interrupts    
    HAL_UART_Receive_IT(huart, (uint8_t*)rx, rx_length);
}

void serial_baud(serial_t *obj, int baudrate)
{
    struct serial_s *obj_s = SERIAL_S(obj);
  
    obj_s->baudrate = baudrate;
    init_uart(obj);
}

static void init_uart(serial_t *obj)
{
    struct serial_s *obj_s = SERIAL_S(obj);
    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
    huart->Instance = (USART_TypeDef *)(obj_s->uart);

    huart->Init.BaudRate     = obj_s->baudrate;
    huart->Init.WordLength   = obj_s->databits;
    huart->Init.StopBits     = obj_s->stopbits;
    huart->Init.Parity       = obj_s->parity;
#if DEVICE_SERIAL_FC
    huart->Init.HwFlowCtl    = obj_s->hw_flow_ctl;
#else
    huart->Init.HwFlowCtl    = UART_HWCONTROL_NONE;
#endif
    huart->TxXferCount       = 0;
    huart->TxXferSize        = 0;
    huart->RxXferCount       = 0;
    huart->RxXferSize        = 0;

    if (obj_s->pin_rx == NC) {
        huart->Init.Mode = UART_MODE_TX;
    } else if (obj_s->pin_tx == NC) {
        huart->Init.Mode = UART_MODE_RX;
    } else {
        huart->Init.Mode = UART_MODE_TX_RX;
    }

    if (HAL_UART_Init(huart) != HAL_OK) {
        error("Cannot initialize UART\n");
    }
}

void serial_clear(serial_t *obj)
{
    struct serial_s *obj_s = SERIAL_S(obj);
    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];

    __HAL_UART_CLEAR_IT(huart, UART_FLAG_TXE);
    __HAL_UART_CLEAR_IT(huart, UART_FLAG_RXNE);
}

void serial_clear(serial_t *obj)
{
    struct serial_s *obj_s = SERIAL_S(obj);
    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];

    __HAL_UART_CLEAR_FLAG(huart, UART_CLEAR_TCF);
    __HAL_UART_SEND_REQ(huart, UART_RXDATA_FLUSH_REQUEST);
}

int serial_getc(serial_t *obj)
{
    struct serial_s *obj_s = SERIAL_S(obj);
    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
    
    while (!serial_readable(obj));
    return (int)(huart->Instance->DR & 0x1FF);
}

int serial_writable(serial_t *obj)
{
    struct serial_s *obj_s = SERIAL_S(obj);
    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
    
    // Check if data is transmitted
    return (__HAL_UART_GET_FLAG(huart, UART_FLAG_TXE) != RESET) ? 1 : 0;
}

void serial_clear(serial_t *obj)
{
    struct serial_s *obj_s = SERIAL_S(obj);
    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
    
    huart->TxXferCount = 0;
    huart->RxXferCount = 0;
}

void serial_putc(serial_t *obj, int c)
{
    struct serial_s *obj_s = SERIAL_S(obj);
    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
    
    while (!serial_writable(obj));
    huart->Instance->DR = (uint32_t)(c & 0x1FF);
}

int serial_readable(serial_t *obj)
{
    struct serial_s *obj_s = SERIAL_S(obj);
    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
    
    // Check if data is received
    return (__HAL_UART_GET_FLAG(huart, UART_FLAG_RXNE) != RESET) ? 1 : 0;
}